my wife cooks more because she the better cook, and because she gets home earlier and can start so the kids are fed. In the summers I cook more because grilling, using the pizza over, etc.
as far as which country the men cook more...it didn't surprise me at all. some italian men, especially the old schools, take it very seriously. i remember making pasta with my grandfather in his basement. churning out the pasta onto a large tray so it could dry out. he had a huge preserve room in his basement, grew a lot of his own fruit and vegetables, etc.